JP2014118912A - Sealing device of fuel piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device of fuel piping, which is attachable and detachable to/from fuel piping and besides, suppresses the leakage of lubrication oil to the outside.SOLUTION: The sealing device of the fuel piping includes a sealing member 160 spirally wound around the external periphery of the fuel piping which supplies fuel to an injector, and a cover 140 for blocking a through-hole of the fuel piping 120, the through-hole being formed in a cylinder head or a rocker cover. Inside the cover 140, there is formed a housing chamber 146 for housing the sealing member 160 wound around the external periphery of the fuel piping 120 while the sealing member is compressed into the axial direction and the radial direction of the fuel piping 120. Then, seal performance between the cover 140 and the sealing member 160 is secured by housing the sealing member 160 in the housing chamber 146 of the cover 140 in the compressed state, and the leakage of the lubrication oil to the outside from the cylinder head or the rocker cover is suppressed. Furthermore, since the sealing member 160 is merely wound around the fuel piping 120, the sealing member can be easily removed from the fuel piping 120.

Description

  The present invention relates to a sealing device that ensures sealing performance between a fuel pipe that supplies fuel to an injector and a cylinder head or a rocker cover.

  As described in Japanese Patent Application Laid-Open No. 2007-85260 (Patent Document 1), a fuel pipe of a diesel engine passes through a through hole formed in a rocker cover and is connected to an injector. Since the inside of the rocker cover is provided with a valve operating mechanism of an intake valve and an exhaust valve, it is filled with splashes of the lubricating oil. For this reason, a seal member (oil seal) is provided between the fuel pipe and the rocker cover in order to suppress the splashing of the lubricant oil to the outside.

JP 2007-85260 A

  By the way, in a common rail type diesel engine, in order to inject fuel into a combustion chamber at 2000 bar or more, the structure by which one end of fuel piping is directly connected to an injector is employ | adopted. In this case, flare nuts are attached to both ends of the fuel pipe, and a sealing member cannot be attached later in the middle, so a cylindrical sealing member that is detachably attached to the fuel pipe with a slit formed in the axial direction Can be considered. The reason why the seal member should be detachable is that the seal member deteriorates due to changes over time, and the required sealing performance cannot be maintained. However, in the cylindrical sealing member in which the slit is formed in the axial direction, for example, when the internal pressure of the rocker cover increases due to a temperature rise, there is a possibility that the lubricating oil leaks from the slit joint.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a fuel pipe sealing device capable of suppressing leakage of lubricating oil from a cylinder head or a rocker cover to the outside despite being detachable from the fuel pipe.

  A fuel pipe sealing device includes a seal member that is spirally wound around an outer periphery of a fuel pipe that supplies fuel to an injector, a blocking member that closes a through hole of the fuel pipe formed in a cylinder head or a rocker cover, including. The closing member is formed with a storage chamber for storing the seal member wound around the outer periphery of the fuel pipe in a compressed state in the axial direction and the radial direction of the fuel pipe.

  According to the present invention, since the seal member is merely wound around the outer periphery of the fuel pipe, it can be easily attached to and detached from the fuel pipe. Further, since the closing member that closes the through hole of the cylinder head or the rocker cover accommodates the sealing member wound around the fuel pipe in a compressed state, the sealing member has a restoring force to return to the natural state. By utilizing this, the sealing performance between the fuel pipe and the closing member is ensured. For this reason, leakage of lubricating oil from the cylinder head or the rocker cover to the outside can be suppressed.

It is sectional drawing which shows an example of the sealing apparatus of fuel piping. The detail of a cover is shown, (A) is a top view, (B) is a longitudinal cross-sectional view. The detail of a sealing member is shown, (A) is a perspective view, (B) is a front view. The cover is divided into two parts, (A) is a top view, and (B) is a longitudinal sectional view. It is sectional drawing which shows the other example of the sealing apparatus of fuel piping.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows an example of a fuel pipe sealing device that penetrates a rocker cover of a diesel engine.

  An injector 110 that injects fuel toward a piston cavity (not shown) is attached to a cylinder head 100 of the diesel engine. The injector 110 is, for example, an electromagnetic fuel injection valve in which a coil operates in response to a drive signal from an injector driver of a control unit, and a needle valve that is biased in a valve closing direction lifts and injects fuel. . For this reason, the fuel adjusted to a predetermined pressure is supplied to the injector 110 so that fuel proportional to the valve opening time of the needle valve is injected.

  For example, one end of a fuel pipe 120 to which fuel is supplied from a common rail (not shown) is connected to the base end 112 of the injector 110, that is, the portion farthest from the tip 114 facing the combustion chamber. Both ends of the fuel pipe 120 are formed with enlarged diameter portions 122 by bulging or the like, and flare nuts 124 are attached to portions sandwiched between the enlarged diameter portions 122 so as to be detachably connected to the injector 110 and the common rail. ing.

  On the upper surface of the cylinder head 100, a valve operating mechanism (not shown) for an intake valve and an exhaust valve, that is, a rocker cover 130 for accommodating a camshaft, a rocker arm and the like is fastened. A through hole 132 for allowing the fuel pipe 120 to penetrate is formed on the upper surface of the rocker cover 130. The through hole 132 of the rocker cover 130 is closed by a cover 140 as an example of a closing member.

  The cover 140 is made of a metal member, and, as shown in FIG. A cylindrical part 144 having a cylindrical shape is integrally formed. The flat plate portion 142 has a substantially rhombus shape in plan view, and insertion holes 142A through which bolts 150 for detachably fastening the cover 140 to the rocker cover 130 are inserted at both ends in the longitudinal direction. In addition, in the cylindrical portion 144, a storage chamber 146 is formed that stores, in a compressed state, a seal member 160 that is wound around the outer periphery of the fuel pipe 120 and is made of an elastic member such as rubber. .

The cover 140 is not limited to the shape shown in the figure, and may have any shape as long as the through hole 132 of the rocker cover 130 can be closed.
As shown in FIG. 3, the seal member 160 is wound in a spiral state in a natural state (natural length state), and the one end 162 located on the cylinder head 100 side has an outer diameter toward the end portion. The taper is gradually reduced in diameter. Since the seal member 160 is spirally wound in a natural state, an operation of attaching the seal member 160 to the fuel pipe 120 can be facilitated. Further, as shown in FIG. 3, the wire of the seal member 160 has a substantially rectangular (quadrangle) cross section, but may be a simple circle. The seal member 160 is not limited to the shape shown in FIG. 3, and may be linear (string-like) in a natural state, for example.

  In order to accommodate such a seal member 160, the accommodation chamber 146 of the cover 140 has a shape in which the portion close to the rocker cover 130 follows the taper shape of the seal member 160, as shown in FIG. It is formed in a tapered shape that gradually decreases in diameter toward the bottom surface of the flat plate portion 142. Therefore, when the sealing member 160 wound around the fuel pipe 120 is accommodated in the accommodating chamber 146 of the cover 140, the tapered surface of the sealing member 160 is pressed upward by the tapered surface of the accommodating chamber 146. It becomes easy to accommodate in the storage chamber 146 in a compressed state in the axial direction.

  As shown in FIG. 4, the cover 140 is configured to be divided into two parts by a plane passing through the axis of the fuel pipe 120, that is, a longitudinal section passing through the axis of the fuel pipe 120. In addition, pins 148 </ b> A and engagement holes 148 </ b> B that are engaged with each other are formed on the split surface of the cover 140, that is, the mating surface of the two components. Therefore, the cover 140 made of two parts can be retrofitted to the fuel pipe 120 penetrating the through hole 132 of the rocker cover 130. At this time, the two parts of the cover 140 are integrated while positioning each other by engaging the pin 148A and the engagement hole 148B, so that the bolt 150 for fastening this to the rocker cover 130 is integrated. The number of can be reduced.

In addition, when it is necessary to further improve the sealing performance between the rocker cover 130 and the cover 140, a gasket (not shown) may be sandwiched therebetween.
Here, the operation and effect of the sealing device will be described.

  The operator inserts one end of the fuel pipe 120 into the inside of the through hole 132 of the rocker cover 130, closes the other end of the fuel pipe 120 to the pipe connection port of the common rail, and tightens the flare nut 124, thereby Both ends of 120 are connected to the injector 110 and the common rail. In addition, the worker attaches a spirally wound seal member 160 to a predetermined location on the outer periphery of the fuel pipe 120, and engages the pin 148A and the engagement hole 148B of the cover 140 made of two parts from the outside. Match. At this time, since the taper surface of the seal member 160 is pressed and compressed by the taper surface of the storage chamber 146 of the cover 140, the seal member 160 can be easily stored in the storage chamber 146 while being compressed in the axial direction. .

  Next, the operator inserts the bolt 150 into the insertion hole 142 </ b> A of the cover 140 and screws the male screw into the female screw of the rocker cover 130, thereby fastening the cover 140 to the rocker cover 130.

  In this state, the seal member 160 spirally wound around the outer periphery of the fuel pipe 120 is accommodated in the accommodation chamber 146 of the cover 140 while being compressed in the axial direction and the radial direction of the fuel pipe 120. For this reason, the fuel pipe in which the wire rods of the seal members 160 adjacent in the axial direction are closely joined by the restoring force that the seal member 160 tries to return to the natural state, and the wire rods of the seal member 160 are arranged in the radial direction The outer peripheral surface of 120 and the inner peripheral surface of the accommodation chamber 146 of the cover 140 are pressed. Therefore, the sealing performance between the fuel pipe 120 and the cover 140 can be ensured. Here, the cover 140 has a two-part structure. However, since the seal member 160 is pressed against the inner peripheral surface of the storage chamber 146, the lubricating oil does not leak from the mating surface. Furthermore, since the seal member 160 can be easily removed from the fuel pipe 120, for example, even if the seal member 160 deteriorates due to aging, it can be easily replaced.

  On the other hand, when the fuel pipe 120 is removed from the injector 110, the following may be performed. That is, the operator removes the bolt 150 that fastens the cover 140 to the rocker cover 130 and pulls the cover 140 in the longitudinal direction while moving the cover 140 upward. At this time, when a force larger than the urging force of the seal member 160 is applied, the cover 140 is divided into two parts, and the cover 140 can be removed from the fuel pipe 120. And while removing the sealing member 160 from the outer periphery of the fuel piping 120, the flare nut 124 attached to the both ends of the fuel piping 120 is loosened, and the connection between the fuel piping 120, the injector 110, and the common rail is released. Thereafter, the fuel pipe 120 is moved upward, and one end thereof is taken out from the rocker cover 130.

  Some injectors 110 connect the fuel pipe 120 not from the base end 112 but from the side thereof. In this case, as shown in FIG. 5, a through hole 102 facing the fuel supply port 116 of the injector 110 may be formed on the side surface of the cylinder head 100, and a cover 140 may be attached to the opening. Since the cover 140 and the like are the same as those in the previous embodiment, the description thereof will be omitted to avoid redundant description. If necessary, refer to the description of the previous embodiment.

  The sealing device described above can be applied to a diesel engine that is not a common rail type. Moreover, this sealing device can be applied not only to a diesel engine but also to an in-cylinder injection type gasoline engine that directly injects fuel into a combustion chamber.

DESCRIPTION OF SYMBOLS 100 Cylinder head 102 Through-hole 110 Injector 120 Fuel piping 130 Rocker cover 132 Through-hole 140 Cover (blocking member)
146 Storage chamber 148A Pin 148B Engagement hole 160 Seal member 162 One end

Claims (6)

A sealing member spirally wound around the outer periphery of a fuel pipe for supplying fuel to the injector;
The seal member wound around the outer periphery of the fuel pipe has a storage chamber for storing the seal member in a compressed state in the axial direction and the radial direction of the fuel pipe, and penetrates the fuel pipe formed in the cylinder head or the rocker cover. A closing member for closing the hole;
A fuel pipe sealing device comprising: The sealing member is spirally wound in a natural state,
The fuel pipe sealing device according to claim 1. One end of the seal member has a tapered shape in which the outer diameter gradually decreases toward the end,
The accommodating chamber of the closing member has a shape in which a portion close to the cylinder head or the rocker cover follows the tapered shape of the seal member,
The fuel pipe sealing device according to claim 2, wherein: The closing member can be divided into two on a plane passing through the axis of the fuel pipe.
The fuel pipe sealing device according to any one of claims 1 to 3, wherein Pins and engagement holes that are engaged with each other are formed on the dividing surface of the closing member, respectively.
The fuel pipe sealing device according to claim 4. A gasket is sandwiched between the closing member and the cylinder head or the rocker cover.
The fuel pipe sealing device according to any one of claims 1 to 5, wherein: